Late afternoon flying

[Night Crawler]

I think this is the right place to put this.
After some practice on the flight sim (FSX and Clearview demo) I decided to take the Cessna out. Was a lil breezy for my likeing so i left it till about 6, just before the sun started to go red.
Took a walk up the field and there was just a slight breeze. That was it. Got everything ready, picked my spot and decided to go for it.
Had to abort my first attempt because the plane hit a bump in the grass and knocked it off course.
So I picked a different spot and off she went. Took off nice and gentle, then into a steep ish climb. Nice and easy, but a little choppy. The breeze was a bit stronger up there.
Got up to a nice hight, dropped the throttle to about 1/3 and flew around for about 10 mins. I started getting a bit giddy because she was flying so nice, but i managed to keep my cool.
Managed to do a couple of full and half loops (i know i shouldnt, but couldnt help myself). Seemed slightly under powered to do them neat, but they looked ok.
I brought her in to land, almost gliding it in. Touched the grass and flip. Over it went. I caught a divvet in the grass. No damage at all, just bent the nose wheel under a bit.
I stopped for a ciggie and then decided to go for it again.
Powered her up, back on the elevator and off the ground. Flew for about 20 meters at just a foot off the grass, then up she went. Got her nice and high, eased up on the throttle and practiced flying towards, away and across. A little jumpy, but otherwise it was a nice smooth flight. Musthave been another good 10 mins or so.
Brought her in to land again, slow and smooth, touched the grass and almost flipped her again. She needs really short grass to land on.
So, a nice evening of flying and no crashes at all.
I do have a couple of questions though in my next post

[Steve Houghton 1]

Sounds good to me

[Night Crawler]

Ok, while i was flying at 1/3 throttle, everything was nice and flat. As soon as i throttled up, the pland just wanted to pitch up and climb. If she had the power, she would loop on her own.
What would be causing this?
Im thinking, C og G too far forward and too much up elevator?
But i just wanna double check before i start fiddling.
Also, does anyone know where i can get piano wire or spring steel rod in stoke on trent? I wanna make up a new, stronger and springier landing gear.

[Steve Hargreaves - Moderator]

Sounds like you might need a touch of downthrust on the motor....a high wing model of this type will always climb under power but yours sounds like its a bit too keen to gain height.....see if you can use some washers under the motor mounting to tilt the front of the motor down a bit (I'm not familiar with the model so can't say exactly how or where you should fit the washers!!!)

 

A good model shop near Stoke is Tony Hills place...All Electric in Talke Pits....a bit out of Stoke just up the A34 but a great guy....he will sell you some piano wire & offer good advise too...

 

All Electric RC here

[Night Crawler]

Cheers Steve H. I'll give that a go and report back.
I tried look for All Electric the other day. I must have driven straight past it. Have you been? Is it easy to miss?

[Biggles' Elder Brother - Moderator]

Well first of all, well done!

 

I'm assuming this is an electric powered model - right?

 

OK, first thing. The model should fly level at some throttle setting - we call that the "cruise speed". Throttle above that and it should climb, throttle lower than that and (unless you hold the nose up with the elevator) the model will go slightly nose down and decend.

 

Normally we would want the cruise to be about 2/3 throttle or so. Now you seem to have the cruise at 1/3 throttle - that would be OK if the model were very overpowered but that isn't likely to be the case. So what is causing this?

 

Well there are two possible explainations:

 

1. The tailplane is slightly out of line with the wing and giving too much "up". We call this the tailplane incidence. On most models the tailplane is either neutral (i.e. in line with the wing) or very slightly negative - ie the front edge is very slightly lower than the back edge.

 

2. The thrust line of your motor is out of line - i.e. your motor is pointed slightly upwards - although TBH this can happen even if the motor is level, a lot of models need the motor pointed very slightly down.

 

Which one? Difficult to say without actually flying the model, or at least seeing it fly. So what I'd do if I were you.

 

Assume its 1. the fix (at least temporary) for this is to put in a bit of "down" trim on your transmitter. Just a couple of clicks at first. Then fly it and see. Add more "down" trim until the model cruises level at about 2/3 throttle - if possible.

 

Land, take a look at the elevator. If you have only added a little bit of trim and all is well - fine you've solved it. For now at least. If you have had to put in loads of "down" trim - or even run out of trim before the cruise was satisfactory, we need to look at 2.

 

To fix 2. add one washer on the bolts behind the upper motor mount/s thus tilting the motor very slightly more downward. Centre your elevator trim and try again. If necessary add a second washer.

 

The aim is to get the model to fly straight and level at about 2/3 throttle with no excessive elevator trim in.

 

Finally, you asked about CoG. I assume you've got it where the instructions tell you to? Its very unlikely to be too far back or you would have really struggled to control the model.

 

Try these ideas out and let us know how you get on - once we have the model behaving itself we can do some simple tests to check the thrust line and optimise the CoG a bit. But let's get this cruise setting right first.

 

BEB

[Night Crawler]

Cheers for that beb. I'll give your suggestions a go and see what happens.
The model in question is an Art Tech Cessna 182. Running an Art Tech C2830-21 brushless motor (7.4v 80W and no load rpm 1500kv), running a nylon (i think) 3 blade 8x6 prop.
Unfortunatly the instructions didnt mention anything about C of G. I just adjusted it according to what the guy in the shop suggested.
When i get internet access on a computer, i'll get some pics and vids up.
Appart from this, she flew very nice. Only other downside is, its easly influenced by the slightest breeze. I guess thats the problem with foamies.

[Steve Hargreaves - Moderator]

Yeah...All Electric are not that easy to find......it doesn't say All Electric over the door cos its actually Tony Hill Models....but then it doesn't say that over the door either.... Yep you need very good psychic powers to spot this shop!!!

 

However...for those without the necessary powers this is what you do......!!

 

Out of Stoke on the A34......across the roundabout over the A500. Past the Little Chef....1st exit at the roundabout.....3rd exit at the next one. You are now heading into Talke (may God have mercy on your soul) & its all bollards & traffic calming from now on....you go through (I think) 3 "priority to oncoming traffic" type junctions & the shop is immediately on your left after the third one......its on a corner of a row of terraces.....he had a Breitling Sukhoi in the window last time I was there!!! If you see a row of shops on yer left you've gone too far!!!

 

Tony (& Anthony his son!!) is a good guy & will help you out I'm sure.....Tony's been flying electric models since well before they became mainstream.....

[Romeo Whisky]

My Multiplex Gemini tended to balloon upwards when I opened the throttle and still did after checking CG and adding more downthrust etc as above. My solution was to mix in a little down-elevator with the throttle and this seems to work well throughout the throttle range. Just mix in a little at a time until it is comfortable. Obviously don't overdo it!

[Night Crawler]

Hey Steve. Cheers for that. I managed to find it after driving up and down High Street 3 or 4 times. Dunno what the aircraft in the window was, but it was red and white (i think). I got a 2 blade prop, some slightly bigger wheels, some piano wire and lots of advice.
I have put a thin washer behind the engine mount to tilt the motor down very slightly. I'll be takeing a walk down to the field in a bit to see if its ok to fly later on. Actually, looking out the window, i think it might be a little too breezy. The trees are moving around a bit. Will see what its like later though.
I cant do any mixing on my tx. Its only a basic one. Only thing i can do is adjyst the trim each time i throttle up or down. I'll give it a go when i can and see how things turn out.

[Steve Hargreaves - Moderator]

If you think its too windy, it probably is so don't fly......!!

 

Not familiar with the model but does it have ailerons? If it is only rudder/elevator then light winds are more or less essential. R/E models really do take their time to turn back into wind & while they are doing it they are getting further & further away from you as they are blown away by the wind.

 

After a very short time you are trying to control a dot on the far horizon......I know from bitter experience when I first started many moons ago......

 

Ailerons give you much more control & will allow you to bully the aeroplane into position somewhat.....

[Night Crawler]

Just got back in from a nice walk into town. Definatly too windy. It doesnt look too bad watching the trees from the window, but once out in open space its just too much. Too much for most aircraft i think. So no flying today
See what its like tomorrow. Not seen the weather report yet, but fingers crossed it will be ok.
Girlfriend is working tonight, so i have a few hours to play around with the cessna and get some test figures from the motor and new prop.
Oh, the cessna is full 4 channels. But its a foamie (EPP i think is what its called) and will get blown away before i know it.